Toyota Motor Corp. turned to injection molding to reduce both weight and costs in the seats for its 2021 Sienna minivan.

The automaker"s work won it the top award in the Altair Enlighten Award module category, presented Aug. 4.

The free-standing, two-occupant back frame reduced the number of parts for the seat back to one from 15, cut production costs by 15 percent and reduced weight by 30 percent, engineering firm Altair said, saying the module was the first of its kind in the industry.

The Enlighting Award honors products and vehicles for outstanding lightweighting efforts.

Other recognition for plastics went to:

• Mubea, a German supplier specializing in lightweight components, won an Enlighten Award for Enabling Technology for its glass-fiber-reinforced leaf spring. The component is used mostly in the suspension systems of heavy trucks. The spring weighs up to 75 percent less than a typical multileaf steel spring.

• DuPont Co."s Betaseal X2500 adhesive, which joins thermoplastic inner and outer panels, was named runner-up in the enabling technology category.

• A Future of Lightweighting award went to Marelli. The company"s sheet compression molded suspension steering knuckle reduces weight by 25 percent over the aluminum version and by 50 percent over steel knuckles.

• Nissan took runner-up honors in the Future of Lightweighting for an aluminum and carbon fiber body panel design that can reduce weight by about 50 percent over steel panels.

The top vehicle honor went to the electric Harley-Davidson Livewire motorcycle while the 2020 Nissan Sentra was a runner-up for improving safety without increasing weight by using a variety of materials in different applications.

Altair, the suburban Detroit software engineering firm specializing in product development, has handed out the awards for the past seven years.

"As we sit at the crossroads of science, engineering, art and design, creating a more sustainable future is the essence of Altair as we are a pioneer in lightweighting technologies and methodologies," Altair CEO James Scapa said in a statement.

"I am proud to see that the Altair Enlighten Awards have become a sought-after recognition that acknowledges the world"s greatest automotive lightweighting innovations while inspiring interest from industries, engineers, policymakers, educators, students and the public."

Altair traditionally announces its recipients during the annual CAR Management Briefing Seminars, an industry gathering in Traverse City, Mich.

Because of the coronavirus pandemic, the live seminars were canceled this year. They are being held online Aug. 4-5.